We assessed the influence of some environmental conditions (temperature and rainfall) on the litterfall and BAI (basal area increment), in three close forests in the Montseny massif (NE part of the Iberian peninsula, Spain). Two of them are composed of deciduous species Fagus sylvatica and Quercus petraea, and the other one is a Mediterranean evergreen species, Quercus ilex. We have collected monthly data about litterfall and radial growth since 2007. For each forest there are tree plots, with litterfall traps and band dendrometers. This data has been related with the meteorological parameters of meteorological station closed to the study area. Our results show that F. sylvatica recorded the biggest drop in annual litterfall (6 Mg·ha-1·year-1), followed by Q. ilex (4.34 Mg·ha-1·year-1) and Quercus petraea (4.4 Mg·ha-1·year-1) and that all the values were similar to those observed in other forests and mountains with the same state of maturity. Regarding the litterfall, the investigation found a decline in the leaves fall in deciduous trees in years with hot summers. In addition, these warm summers produce a decline in the F. sylvatica BAI, but not in Q. petraea. Concerning growth, we found that Q. petraea increases the BAI on the study period while F. sylvatica does not. In conclusion, we believe that in the future Q. petraea will be more tolerant to the warm conditions than F. sylvatica, making the former a possible replacement of the second species